High in Argentina's Andes Mountains, Laguna (lake) Verde shows off a range of colors created by a host of microscopic organisms in this astronaut photo taken from the International Space Station.
Laguna Verde (58 kilometers wide, 36 km long) often appears green, giving rise to its name. The lake floor lies at 4,095 meters (13,438 feet) above sea level, whereas the peak of the local volcano (west of the lake, not shown) reaches more than 3,000 meters higher (6,818 meters or 22,368 feet above sea level).
The reason for the color differences is that many different families of salt-loving organisms occupy hyper-saline lakes such as Laguna Verde. These microscopic organisms appear as different colors, often bright, depending on the salinity and temperature of each water body or sub-basin.
The rest of the lake floor is dry and appears white from the build-up of thick salt deposits. Parallel lines around the southern sub-basin (Laguna Negro) indicate prior shorelines of this shrinking water body. Evaporation removes water but leaves ephemeral shorelines marked with white salt.
Image courtesy of NASA.